The present invention relates to a differential assembly and more particularly to a differential assembly having a limited slip device with adjustable pre-load.
Differential assemblies having a limited slip device are known in the art. FIG. 1 depicts a differential assembly having a limited slip device according to the prior art. Differential pinions 5 and side gears 7 are disposed within a differential case 6. A multiple-disc clutch pack 4 is disposed between one or each of the side gears 7 and the differential case 6. The differential case 6 may have axial grooves or splines to prevent rotation and allow axial displacement of friction discs of the clutch pack 4. Similarly clutch plates are splined onto the side gears 7 and interposed between the friction discs. A spring is normally disposed between the side gears 7 to urge the side gears 7 apart and cause frictional engagement in the clutch pack. However, a Belleville spring 8 may be disposed between the clutch pack 4 and either the side gear 7 or differential case 6. The friction between the friction discs and clutch plates limits the amount that the side gears 5 may slip relative to the differential case 6. However, the prior art assemblies do not facilitate selective adjustment of the clutch pack 4 preload. Moreover, the prior art fails to provide a means to adjust the clutch pack 4 preload after the differential is assembled and provide easy readjustment after a portion of its service life has expired or the ability to easily externally adjust the clutch pack 4 preload from the differential case 6.
The present invention is directed to a differential assembly having a limited slip device with adjustable preload. The differential assembly includes a differential case with pinion and side gears disposed therein. The clutch pack is disposed between at least one of the side gears and the differential case to retard relative rotation there between. An adjustment collar is disposed between the clutch pack and the differential case to adjust the preload of the clutch pack. Elongated slots are formed through the differential case to provide external access to spanner slots formed in the adjustment collar. A tool may be inserted through the elongated slots to engage the spanner slots and selectively rotate the adjustment collar to adjust the pre-load of the clutch pack. The arrangement of the present invention provides the ability to uniformly adjust the pre-load of the clutch pack with access external of the differential case.